1. Field of the Invention
The invention relates to a preparation for shrink-proofing wool based on organopolysiloxanes.
2. Description of the Prior Art
It is well-known that wool in the untreated state shrinks and felts when washed in an aqueous liquor. In order to counteract this shrinkage and felting, chemical treatments have been recommended in which the structure of the wool is changed or in which finishes are used which contain resin that deposits on the surface of the wool fibers so as to envelop them. By both processes, however, products are obtained whose so-called "hand" is regarded as unpleasant by the consumer.
It has also been disclosed that the shrinkage of wool on washing can be decreased by treatment with organosilicon compounds. Such processes are described in British Pats. Nos. 594,901, 613,267, and 629,329, wherein the wool is treated with certain silanes.
A process for preventing the shrinkage of wool is described in British Pat. No. 746,307, in which the wool fibers are finished with certain organopolysiloxanes. While some degree of shrinkproofness can be achieved by these means, the effect does not stand up to laundering.
In a series of further publications, for example, German Offenlegungsschriften Nos. 22 42 297, 23 35 751, and 25 23 270, processes are disclosed for shrinkproofing keratin fibers by applying organopolysiloxanes, an essential characteristic of these processes residing in the amino-group content of these compounds.
For example, the process according to German Offenlegungsschrift No. 22 42 297 is characterized by the fact that units of the general formula EQU R.sub.n.sup.5 SiO.sub.(4-n)/2
are used as organopolysiloxanes, in which:
n has an average value of 1.9 to 2.1, and PA0 R.sup.5 is an organic residue which is linked to silicon by a silicon-carbon bond PA0 wherein 0.25 to 50% of the R.sup.5 substituents are monovalent residues with fewer than 30 carbon atoms which contain at a distance of at least 3 carbon atoms from the silicon atom: PA0 and wherein the remaining R.sup.5 substituents are monovalent hydrocarbon residues, halogenated hydrocarbon residues, carboxyalkyl residues or cyanoalkyl residues with 1 to 30 carbon atoms, of which at least 70% consist of monovalent hydrocarbon residues with 1 to 18 carbon atoms. PA0 A is a polydiorganosiloxane with terminal hydroxy groups linked to silicon atoms and with a molecular weight of at least 750, PA0 B is an organosilane of the general formula EQU R.sup.6 SiR.sub.n.sup.7 X.sub.3-n PA0 in which PA0 R.sup.6 is a monovalent group which is built up from carbon, hydrogen, nitrogen and, optionally, oxygen, contains at least 2 amino groups and is linked to silicon through silicon-carbon bonds, PA0 R.sup.7 is an alkyl group or an aryl group, PA0 X is an alkoxy group with 1 to 4 carbon atoms inclusive, and PA0 n is 0 or 1, and/or a partial hydrolysate and condensate of the organosilane. PA0 R.sup.9 represents lower alkyl residues with 1 to 7 carbon atoms, PA0 n is a whole number not less than 2, PA0 p is 0, 1 or 2, PA0 m is 0, 1 or 2, PA0 the sum of m+p has a value of 0 to 2, PA0 x is a whole number not less than 1, PA0 y and z in each case are 0 or a whole number, with the proviso than PA0 (a) 1 to 50 wt % of organopolysiloxanes, which consist of PA0 (b) 50 to 99 wt % of water, optionally with emulsifiers and/or organic solvents and, optionally, customary additives. PA0 R.sup.2 represents an alkyl residue, a mercaptoalkyl residue or a mercaptoaryl residue. R.sup.2 may also be hydrogen residue or a partial oxygen residue O.sub.0.5 or an anionic group linked to the silicon atom through carbon atoms. If several units of formula (II) are present, R.sup.2 may have the same or different meanings in the various units. Here also, the methyl residue is preferred as the alkyl residue. Examples of alkyl and mercaptoalkyl or mercaptoaryl residues are the methyl, ethyl, mercaptomethyl, 2-mercaptoethyl, 3-mercaptopropyl or 4-mercaptophenyl residues.
at least 1 imino group, and PA1 at least 1 primary or secondary amino group having the formula --NX.sub.2 PA1 wherein X is a hydrogen atom, an alkyl group with 1 to 30 carbon atoms or an aryl group, PA1 in which at least 50% of the organic substituents of the polydiorganosiloxane are methyl groups and PA1 in which the other substituents are monovalent hydrocarbon groups with 2 to 30 carbon atoms, and PA1 when y=0, p is at least 1 and PA1 when z=0, m is at least 1 and x is greater than the sum of y+z. PA1 (aa) 90 to 99.8 mole % of units of the formula EQU R.sub.n.sup.1 SiO.sub.(4-n)/2 (I) PA1 in which PA1 (ab) 0.2 to 10 mole % of units of the formula EQU R.sup.2 SiO.sub.3/2 (II) PA1 in which
A process for treating keratin fibers is known from German Offenlegungsschrift No. 23 35 751, which is characterized by the fact that the organopolysiloxane composition contains the product obtained by mixing components (A) and (B) wherein
It is stated in this German Offenlegungsschrift that the two components of the mixture should be reacted if the fibers are to be treated from an aqueous medium. As practical experiments have shown, however, it is not possible to prepare stable, aqueous emulsions from such reaction products. Gel-like reaction products are formed which cannot be transformed into emulsion form. They are therefore not suitable for shrinkproofing wool from an aqueous phase.
If these reaction products are used in the form of organic solutions, the effect which can be achieved turns out to be too slight for them to be successfully used under practical conditions. Moreover, through the action of moisture from the air, a siloxane gel precipitates from the solvent-containing liquor and clogs up the equipment for treating the wool.
Furthermore, a process is known from German Offenlegungsschrift No. 17 69 249 for treating fibrous materials, e.g., wool, in which organosiloxanes containing mercaptopropyl groups are used in the form of an emulsion. With these compounds, however, it is only possible to decrease the soilability. The compounds are not suitable for making wool shrinkproof.
In another process, a hair-treating material is known from German Offenlegungsschrift No. 16 17 443, which is based on organosilicon compounds and characterized by the fact that it contains an organosiloxane copolymer of the general formula ##STR1## in which R.sup.8 represents alkyl residues with at least 8 carbon atoms,
These compounds also are not suitable for shrinkproofing wool. The structure of an organopolysiloxane, which is suitable for shrinkproofing wool, could not be derived from these prior publications.